// You can find the Turtle API reference here: https://turtletoy.net/syntax
Canvas.setpenopacity(1);

const fillMode = 0; //min=0 max=2 step=1 (Randomized square, Randomized circle, Cone)
const minimumSize = 10; //min=2 max=30 step=1
const maximumSize = 10; //min=2 max=30 step=1
const nested = 5; //min=0 max=10 step=1
const fillTo = 85; //min=50 max=100 step=1
const polygonCount = 500; //min=1 max=1000 step=1
const polygonEdges = 6; //min=3 max=30 step=1
const polygonFill = 3; //min=0 max=3 step=1 (None, Linear, Absolute clipped, Absolute unclipped)
const scaleGradient = 2; //min=0 max=2 step=1 (No, Yes, Yes: inverted)
const stash = 0; //min=0 max=2 step=1 (Random, Center on top, Center on bottom)

let minSize = Math.min(minimumSize, maximumSize);
let maxSize = Math.max(minSize, maximumSize);

// Global code will be evaluated once.
const turtle = new Turtle();
const polygons = new Polygons();

const pi2 = Math.PI * 2;

const add2 = (a, b) => [a[0]+b[0], a[1]+b[1]];
const clip = (a, min=0, max=1) => Math.max(0, Math.min(1, a));

const ptGenerator = ( //a function that returns an [angle, radius] polor coordinate
    fillMode == 0? (x = (Math.random() * 2 - 1) * fillTo, y = (Math.random() * 2 - 1) * fillTo) => [x == 0? (y > 0? Math.PI/2: (4*Math.PI/3)) : Math.atan(x/y) + (x < 0? Math.PI:0), (x**2+y**2)**.5]
    : fillMode == 1? () => [Math.random() * pi2, Math.sqrt(Math.random()) * fillTo]
    : () => [Math.random() * pi2, (Math.random())**2 * fillTo]
);

const polygonStash = [];

// The walk function will be called until it returns false.
function walk(i) {
    if(i < polygonCount) {
        let pt = ptGenerator();
        let scaleScale = 1;
        if(scaleGradient > 0) {
            scaleScale = (pt[1] / fillTo) / 1.2;
            if(scaleGradient == 2) scaleScale = 1 - scaleScale;
            
            if(polygonFill > 1) scaleScale = 1 - scaleScale;
        }
        polygonStash.push([
            [Math.cos(pt[0]) * pt[1], Math.sin(pt[0]) * pt[1]],
            polygonEdges,
            nested,
            (minSize + (Math.random() * (maxSize - minSize))) * scaleScale,
            maxSize,
            pi2 * Math.random(), pt[1]
        ]);
        return true;
    }
    if(i == polygonCount && stash > 0) {
        polygonStash.sort((a,b) => (a[6] < b[6]? 1: -1) * (stash == 2? -1: 1));
    }
    nestedPolygon(...polygonStash.pop());
    return polygonStash.length > 0;
}

function nestedPolygon(position, edges, n, size, maxSize, rotation = 0) {
    for(let i = 1; i <= (polygonFill == 0?1:n); i++) {
        const p = polygons.create();
        let s = 
            polygonFill == 1? size * i/n
            : polygonFill == 2? Math.max(0, -(size - (i*3)))
            : polygonFill == 3? (size - (i*3))
            : size //default
        ;
        s = Math.min(maxSize, Math.abs(s));
        for(let pt of polygon(edges, s, rotation)) {
            p.addPoints(add2(position, pt));
        }
        p.addOutline();
        polygons.draw(turtle, p);
    } 
}

function *polygon(edges, scale, rotation = 0) {
    for(let i = 0; i < edges; i++) {
        yield [
            Math.cos(pi2 * i / edges + rotation) * scale,
            Math.sin(pi2 * i / edges + rotation) * scale
        ];
    }
}


////////////////////////////////////////////////////////////////
// Polygon Clipping utility code - Created by Reinder Nijhoff 2019
// (Polygon binning by Lionel Lemarie 2021)
// https://turtletoy.net/turtle/a5befa1f8d
////////////////////////////////////////////////////////////////
function Polygons(){const t=[],s=25,e=Array.from({length:s**2},t=>[]),n=class{constructor(){this.cp=[],this.dp=[],this.aabb=[]}addPoints(...t){let s=1e5,e=-1e5,n=1e5,h=-1e5;(this.cp=[...this.cp,...t]).forEach(t=>{s=Math.min(s,t[0]),e=Math.max(e,t[0]),n=Math.min(n,t[1]),h=Math.max(h,t[1])}),this.aabb=[s,n,e,h]}addSegments(...t){t.forEach(t=>this.dp.push(t))}addOutline(){for(let t=0,s=this.cp.length;t<s;t++)this.dp.push(this.cp[t],this.cp[(t+1)%s])}draw(t){for(let s=0,e=this.dp.length;s<e;s+=2)t.jump(this.dp[s]),t.goto(this.dp[s+1])}addHatching(t,s){const e=new n;e.cp.push([-1e5,-1e5],[1e5,-1e5],[1e5,1e5],[-1e5,1e5]);const h=Math.sin(t)*s,o=Math.cos(t)*s,a=200*Math.sin(t),i=200*Math.cos(t);for(let t=.5;t<150/s;t++)e.dp.push([h*t+i,o*t-a],[h*t-i,o*t+a]),e.dp.push([-h*t+i,-o*t-a],[-h*t-i,-o*t+a]);e.boolean(this,!1),this.dp=[...this.dp,...e.dp]}inside(t){let s=0;for(let e=0,n=this.cp.length;e<n;e++)this.segment_intersect(t,[.1,-1e3],this.cp[e],this.cp[(e+1)%n])&&s++;return 1&s}boolean(t,s=!0){const e=[];for(let n=0,h=this.dp.length;n<h;n+=2){const h=this.dp[n],o=this.dp[n+1],a=[];for(let s=0,e=t.cp.length;s<e;s++){const n=this.segment_intersect(h,o,t.cp[s],t.cp[(s+1)%e]);!1!==n&&a.push(n)}if(0===a.length)s===!t.inside(h)&&e.push(h,o);else{a.push(h,o);const n=o[0]-h[0],i=o[1]-h[1];a.sort((t,s)=>(t[0]-h[0])*n+(t[1]-h[1])*i-(s[0]-h[0])*n-(s[1]-h[1])*i);for(let n=0;n<a.length-1;n++)(a[n][0]-a[n+1][0])**2+(a[n][1]-a[n+1][1])**2>=.001&&s===!t.inside([(a[n][0]+a[n+1][0])/2,(a[n][1]+a[n+1][1])/2])&&e.push(a[n],a[n+1])}}return(this.dp=e).length>0}segment_intersect(t,s,e,n){const h=(n[1]-e[1])*(s[0]-t[0])-(n[0]-e[0])*(s[1]-t[1]);if(0===h)return!1;const o=((n[0]-e[0])*(t[1]-e[1])-(n[1]-e[1])*(t[0]-e[0]))/h,a=((s[0]-t[0])*(t[1]-e[1])-(s[1]-t[1])*(t[0]-e[0]))/h;return o>=0&&o<=1&&a>=0&&a<=1&&[t[0]+o*(s[0]-t[0]),t[1]+o*(s[1]-t[1])]}};return{list:()=>t,create:()=>new n,draw:(n,h,o=!0)=>{reducedPolygonList=function(n){const h={},o=200/s;for(var a=0;a<s;a++){const c=a*o-100,r=[0,c,200,c+o];if(!(n[3]<r[1]||n[1]>r[3]))for(var i=0;i<s;i++){const c=i*o-100;r[0]=c,r[2]=c+o,n[0]>r[2]||n[2]<r[0]||e[i+a*s].forEach(s=>{const e=t[s];n[3]<e.aabb[1]||n[1]>e.aabb[3]||n[0]>e.aabb[2]||n[2]<e.aabb[0]||(h[s]=1)})}}return Array.from(Object.keys(h),s=>t[s])}(h.aabb);for(let t=0;t<reducedPolygonList.length&&h.boolean(reducedPolygonList[t]);t++);h.draw(n),o&&function(n){t.push(n);const h=t.length-1,o=200/s;e.forEach((t,e)=>{const a=e%s*o-100,i=(e/s|0)*o-100,c=[a,i,a+o,i+o];c[3]<n.aabb[1]||c[1]>n.aabb[3]||c[0]>n.aabb[2]||c[2]<n.aabb[0]||t.push(h)})}(h)}}}